The present invention relates generally to methods for inducing fractures in a subterranean formation and more particularly to methods to place a first fracture with a first orientation in a formation followed by a second fracture with a second angular orientation in the formation according to a time determination.
Oil and gas wells often produce hydrocarbons from subterranean formations. Occasionally, it is desired to add additional fractures to an already-fractured subterranean formation. For example, additional fracturing may be desired for a previously producing well that has been damaged due to factors such as fine migration. Although the existing fracture may still exist, it is no longer effective, or less effective. In such a situation, stress caused by the first fracture continues to exist, but it would not significantly contribute to production. In another example, multiple fractures may be desired to increase reservoir production. This scenario may also be used to improve sweep efficiency for enhanced recovery wells such as water flooding steam injection, etc. In yet another example, additional fractures may be created to inject with drill cuttings.
Conventional methods for initiating additional fractures typically induce the additional fractures with near-identical angular orientation to previous fractures. While such methods increase the number of locations for drainage into the wellbore, they may not introduce new directions for hydrocarbons to flow into the wellbore. Conventional method may also not account for, or even more so, utilize, stress alterations around existing fractures when inducing new fractures.
Thus, a need exists for an improved method for initiating multiple fractures in a wellbore, where the method accounts for tangential forces around a wellbore and the timing of inducing a subsequent fracture.